... and horses have just a hoof, but the horse's hoof is actually one giant toe. There was a time in history when each evolved from a common multiple-toed ancestor, and the horse's middle toe evolved into one big one that we're referring to as a hoof. But, once again, occasionally freak horses will be born with multiple toes sticking awkwardly out of the sides of their feet.

And just as the man with the tail has been worshiped as a mystical being, multiple-toed horses were often regarded as magical status symbols among warriors. Julius Caesar and Alexander the Great were both said to have owned one. The Romans were so impressed by the "toes on a horse thing" that Caesar's was rendered as having at least five, and also a unicorn horn for good measure:

#2. People With Reptile Hearts

Imagine you're struck one day with the most crippling chest pains and you race to the hospital, fearing the worst. The doctor tells you that there's good news and bad news. The good news is that you're not having a heart attack. The bad news is that inside your chest beats the cold heart of a reptile.

That's exactly what happened to a 59-year-old man who was admitted to the hospital with mysterious symptoms that had medical professionals puzzled until they gave him an X-ray and found that he had a full-blown case of snake heart -- a reptilian heart with only three chambers, instead of the usual four.

Getty"As you can see here, you are the devil."

Again, this isn't just a freak deformity that happens to resemble a lizard's heart in the body of a man -- studies of the organ found that it was a genuine genetic throwback, a simple case of evolution getting drunk and forgetting which eon it is. Because we know you think we're making this up, let us just quote the scientists:

"In early stages of embryonic development, the human heart resembles that of a fish .... In later stages of development, the human heart -- now with fully separated atria and a partially separated ventricle -- resembles a reptilian heart. ... To our knowledge, this is only the second reported case of an unusual morphologic variant involving a non-mammalian, reptile-like cardiac anatomy ...."

Getty"The patient is unable to speak Parseltongue, but he can read it."

Wait, you mean this has happened more than once?

And while this sounds like the origin story for a supervillain (this was the plot of the Spider-Man reboot, right?), the only superpower the patient got from it was a horrible pain in the chest and a dependence on prescription medication. We're assuming that if he complained, the doctor's only response would have been "Dude, count your blessings. You made it to age 59 with a snake heart."

Getty"Doctor, the transplant has arrived."

#1. People With Multiple Sets of Boobs

Come on, you knew this was where the article was going. Other mammals have multiple breasts, humans are mammals, you can put two and two together.

So, yes, there have been people who were born with more than just the factory standard two breasts. The hilariously named accessory breast syndrome (we're going to guess a male came up with that) is a throwback to an earlier human ancestor who, like other mammals, had several breasts each so that they could feed a whole bunch of offspring at the same time. Humans tend to only give birth to one or two kids at a time, though, so evolution has decided that we only need an upper limit of two boobs per person.

GettyWe think it knew that bras are only cute in relation to how much material is used.

But, as with all of the other cases on this list, the genes are still hiding in there somewhere, and occasionally they pop up and decide to award someone the grand prize in the boob lottery.

If you're wondering why Internet porn isn't just packed full of four-breasted women, it's because nature, in her infinite wisdom, made it so that accessory breasts are more common among men than women. It's typically harmless, and the extra breasts often aren't even detectable without an MRI (the thing where some men have an extra nipple is not really the same thing). Women often have them removed because they're in the way (sometimes located in the armpit), and because they probably get tired of dudes who hear about it immediately picturing a Total Recall situation.